TWI651244B - Can body, method for manufacturing can body and device for manufacturing can body - Google Patents

Abstract

An object of the present invention is to make the appearance of the can body more excellent. The solution is a tank body having a tank bottom below the tank axis direction, the tank body having: a tank lid forming a tank bottom; the tank body comprising: a body portion, being cylindrical and extending in the direction of the can axis; The curved portion is continuous from the lower end of the body portion and is curved to protrude downward in the inner peripheral side than the body portion; and the crimping portion is formed by winding the end portion of the curved portion opposite to the body portion and the can The peripheral portion of the lid is formed to engage the can lid and the can body, and the lower end of the wound portion is located above the lower end of the curved portion in the direction of the can axis.

Description

Can body, method for manufacturing can body and device for manufacturing can body

FIELD OF THE INVENTION The present invention relates to a can body, a method of manufacturing the can body, and a device for manufacturing the can body.

BACKGROUND OF THE INVENTION In the market, metal cans (beverage cans) for beverages filled with beverages such as beer, refreshing drinks or coffee are diversified, sold, and used by the general consumer. Such a beverage can can be obtained by, for example, forming a metal sheet such as aluminum or steel by DI (Drawing and Ironing) or DR (Drawing and Redrawing) forming. The method integrally forms the can body and the bottom plate (or the top plate). This type of beverage can is called a 2-piece can. Such a two-piece can is manufactured by joining a can lid to a can body filled with a beverage by winding or the like. For example, as the can body of the two-piece can, a neck-in flange is formed in the upper end opening of the flat can body integrally formed from the bottom plate having the shape of the pressure-resistant reinforcement, and As the can lid, a can lid having a simple opening portion called an easy-opening cover, which is smaller than the can body, is used. Then, the can lid with the simple opening portion is wound around the inner curved flange of the can body to form a two-piece can. Further, the can body is formed by bending a thin metal plate into a cylindrical shape to form a can body, and then the bottom plate and the top plate are joined by the sealing or the like to form the can body.

However, in recent years, in place of a PET bottle or a glass bottle, the development of a bottle having a shape like a bottle and being resealable by a lid or the like has been continuously pursued. Such a bottle has a higher light-shielding property against ultraviolet rays than a PET bottle or a glass bottle, and the gas contained in the beverage has a high airtightness. That is, by using the bottle and can, the preservability of the beverage of the contents becomes high. Further, the bottle can have a light weight, is less likely to be broken, and is easier to recycle than a glass bottle. Therefore, in the case of bottle and can, it is feasible to suppress the cost of the container in all life cycles such as use and recycling.

Such a can can be realized, for example, by a two-piece can. For example, in the following Patent Documents 1 to 3, techniques relating to the structure of the mouth and neck are disclosed. On the other hand, in the following Patent Documents 4 to 7, there is disclosed a technique relating to a can and a can, in which a neck portion having a small diameter, a shoulder portion having an inclined surface, and a body having a large diameter are integrally formed. The contents of the beverage or the like are sealed by the bottom cover being wound around the opening at the lower end of the body. Moreover, such a can can also be realized by a 3-piece can. Specifically, in the following Patent Documents 8 and 9, there is disclosed a technique relating to a can, which is formed by winding a skirt portion and a bottom cover each having a slanted cap with a can body portion. Further, in the following Patent Documents 10 and 11, there is disclosed a technique in which the winding portion is folded back toward the inner peripheral side of the can. Prior Technical Literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. Hei. No. 2005-35385. Patent Document 2: Japanese Patent Laid-Open No. Hei. No. 2006-273385. Patent Document 3: Japanese Patent Laid-Open No. 2013-227083. Patent Document 4: Japanese Patent Laid-Open Patent Document 5: Japanese Patent Laid-Open Publication No. JP-A No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. No. [Patent Document 9: Japanese Patent Laid-Open No. 2001-170730] Patent Document 10: Japanese Patent Laid-Open No. Hei 7-33148 Patent Document 11: Japanese Patent Special Fair 5-34064 Bulletin

OBJECTS OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION The above-described Patent Documents 1 to 3 are performed from the upper end opening of a two-piece can, and in the above-mentioned Patent Documents 4 to 7, It is carried out from the bottom plate (top plate) of the 2-piece can. The processing method shown by the latter is considered to be advantageous in the manufacture of cans from the viewpoints of processing time and technical difficulty in processing the neck and shoulder of the reduced diameter.

However, in the can disclosed in Patent Documents 4 to 7, the winding portion that seals the opening of the lower end portion of the body portion and the bottom cover is provided on the bottom side of the can. In this way, when the can is placed on a flat surface, the wound portion is exposed. In this case, since the decorative processing such as painting on the outer peripheral surface of the wound portion is quite difficult, it is necessary to unify the design of the outer surface of the wound portion and the outer surface of the body and the appearance of the outer surface of the body. Quite difficult. Further, since the winding portion is formed by folding the bottom cover and the body toward the outer peripheral side, the structure is protruded outward from the lower end of the body portion, and thus the appearance of the overall shape of the can is degraded.

Moreover, in the cans disclosed in the above-mentioned Patent Documents 8 and 9, by providing a wrap portion that seals the can body portion and the cap between the can body portion and the skirt portion, although the appearance has become less conspicuous However, the enveloping section is still in a state of being seen from the outside. Further, in the same manner as in the above-mentioned Patent Documents 4 to 7, since the winding portion that seals the opening portion of the lower end portion of the can body portion and the bottom cover is provided on the bottom side of the can, when the can is placed, The above-mentioned curling portion will be exposed.

It is also conceivable that the crimping portion is folded back to the inside of the can by the technique disclosed in the above Patent Document 10, whereby the crimping portion is not easily seen from the outside. However, in the above-mentioned Patent Document 10, it is not specifically disclosed how to re-fold the above-mentioned enveloping portion (for example, which type of mold for refolding is used, and which procedure is used to re-fold the enveloping portion). Therefore, even if it is only intended to form the winding portion so that it is difficult to see the winding portion from the outside, there is a fear that molding defects such as flaws or wrinkles may occur on the can body during molding.

Further, in the above Patent Document 11, in the can formed by double-sealing the lid to the open end of the can body, the top of the double-sealed seam tape is formed to be pressed against the can body. The folded end portion is almost the same surface or is pressed into a state inside the can body more than the end edge portion. However, in the above-mentioned Patent Document 11, the end portion of the can body is diffused by being pressed into the inside of the can body by the seam tape. At this time, in the inner surface of the can body, the seam tape will come into contact with the can body. When the seam tape is in contact with the can body, the seam tape rubs against the can body to apply a force to the contact portion, and the contact portion becomes liable to cause embarrassment.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to improve the appearance of the can body, and to manufacture the can body which is excellent in appearance without a molding failure. Means to solve the problem

In order to solve the above problems, according to one aspect of the present invention, a can body having a can bottom at a lower side in a can axial direction is provided, and includes a can lid to form the can bottom; and a can body including a body portion. a cylindrical shape extending in the direction of the can axis; and a curved portion extending from the lower end of the body portion and bent in the inner peripheral side to protrude downward from the body portion; and the crimping portion being longer than the aforementioned The curved portion is further provided on the inner peripheral side, and is formed by winding an end portion of the curved portion opposite to the body portion and a peripheral portion of the can lid, and joining the can lid and the can body, and the aforementioned The lower end of the crimping portion is located above the tank axis direction more than the lower end of the curved portion.

The can body may further include: a shoulder portion extending from the body portion to the upper side, and the can diameter decreasing as approaching from the body portion toward the top along the can axis direction; and the mouth and neck portion, from the shoulder portion It extends on the upper side, has a smaller diameter than the aforementioned body part, and has an opening at the upper end.

Can be configured to the diameter D of the body portion ₁ the diameter D (mm) and the seaming portion ₂ (mm) satisfy the following equation (1). 0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ ... Formula (1)

In order to solve the above problems, according to another aspect of the present invention, a method of manufacturing a can body is a method of manufacturing a can body having a can bottom at a lower side in a can axial direction, comprising: a fixing step of fixing a material to be processed; and forming In the step of molding the fixed workpiece to be processed, the workpiece includes a body portion that is cylindrical and extends in the direction of the can axis to form a side wall portion of the can body, and an inclined portion that is connected from the lower end of the body portion. Extending, and the can diameter is reduced as approaching from the body portion toward the lower side in the direction of the can axis; the cover body forming the can bottom; and the winding portion, by winding the lower end portion of the inclined portion and the cover body The cover portion is formed to engage the cover body and the body portion, and in the forming step, the movement of the winding portion in the radial direction is restrained, and the cover body and the winding portion are oriented in the direction of the can axis The inclined portion that is bent upward is formed into a curved portion that protrudes toward the lower side in the inner peripheral side than the body portion, and the cover body The seaming portion is pushed in until the lower end of the seaming portion becomes the lower portion of the curved ratio of the shaped portion is bent up obliquely upward in the position further-axis direction of the tank.

In the fixing step, the workpiece is fixed by a molding die that restrains the outer peripheral surface of the body portion, and in the forming step, the cylindrical shaft of the molding die is disposed inside the molding die. In the state in which the cover body and the winding portion are in contact with each other, the punch is pushed in from the tank bottom side toward the upper side in the direction of the can axis, thereby forming the curved portion, the punch The punch integrally formed as the following member may include a can lid restraining portion that is configured to be capable of abutting against a lower surface of the lid body, and a seal sealing portion that is provided on an outer peripheral side of the can lid restraining portion, and a concave portion capable of accommodating the sealing portion, and a curved molding portion provided on a peripheral side of the winding sealing portion, having a molding surface that is curved to protrude downward, and a depth of a curved portion in the molding surface is larger than the volume The length of the seal in the direction of the can axis is also large.

The body portion of the can diameter D ₁ diameter D (mm) and the seaming portion ₂ (mm) may satisfy the following equation (1).

0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ ... Formula (1)

The workpiece may further include a shoulder portion extending from the body portion to the upper side, and a can diameter decreasing as approaching from the body portion toward the top along the can axis direction; and a mouth and neck portion from the shoulder portion The upper side is extended on the upper side, has a smaller diameter than the body part, and has an opening at the upper end.

Moreover, in order to solve the above problems, according to another aspect of the present invention, a device for manufacturing a can body is provided in a can body having a can bottom at a lower side in a can axis direction, and includes a molding die for fixing a workpiece; And the punch is disposed on one side of the molding die in the cylindrical axis direction, and the workpiece is molded together with the molding die, and the workpiece includes a body portion and is cylindrical. a side wall portion of the can body extending in the direction of the can axis; the inclined portion is continuous from a lower end of the body portion, and a can diameter decreases as approaching from the body portion downward in the direction of the can axis; the cover body, Forming the can bottom; and the winding portion, by forming a lower end portion of the inclined portion and a peripheral portion of the cover body, and joining the cover body and the body portion, the forming mold is bound by the body part The outer peripheral surface fixes the workpiece, and the punch is a punch integrally formed of the following members, and includes a can lid restraining portion that is capable of abutting against the lower surface of the cover body a winding seal portion provided on the outer peripheral side of the can lid binding portion and having a concave portion capable of accommodating the wind seal portion, and a curved molded portion provided on the outer peripheral side of the seal sealing portion and curved to the can a molding surface that protrudes downward in the axial direction, and a depth of the curved portion in the molding surface is larger than a length of the winding portion in the direction of the can axis, and the punch is provided to be capable of facing the cover body and the aforementioned In a state in which the sealing portion is in contact with each other, the inner circumferential surface of the molding die is moved upward from the tank bottom side.

According to the above-described can body, when the can body is placed on a flat surface, the wound portion provided on the inner peripheral side of the curved portion cannot be seen from the outside. In other words, when the can body is placed on the flat surface, the wound portion is shielded by the curved portion, so that the structure of the wound portion is not included in the appearance of the can. Therefore, it becomes possible to design the appearance of the can body more freely without being limited to the presence of the wind seal portion.

Further, according to the method and the apparatus for manufacturing the can body, when the can body is placed on a flat surface, the wound portion provided on the inner peripheral side of the curved portion cannot be seen from the outside. In other words, when the can body is placed on a flat surface, the wound portion is shielded by the curved portion, so that the structure of the wound portion is not included in the appearance of the can. Further, by the movement of the wind seal portion being restrained in the radial direction, the bending portion of the inclined portion is bent to form the bent portion, and the buckling curve is caused by the compressive force against the in-plane direction. In this way, since the crimping portion is less likely to be stretched in the radial direction, it is possible to suppress the deterioration of the sealing property due to the peeling of the joint portion by the joint portion, and it is possible to prevent the molding failure. Effect of the invention

As described above, according to the present invention, it is possible to further improve the appearance of the can body, and it is possible to manufacture the can body which is excellent in appearance without a molding failure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, constituent elements that have substantially the same functional configurations are denoted by the same reference numerals, and the description thereof will not be repeated.

Further, in each of the directional axes shown in FIGS. 1A to 6 below, the direction C means the tank axis direction of the can body 1, and the direction R shows the radial direction of the can body 1. Hereinafter, in the present specification, the tank axis direction C and the radial direction R are described. In addition, in the present specification, the direction indicated by the arrow in the can axis direction C shown in FIGS. 1A to 6 (that is, the side of the neck portion 23 of the can body 1) is described as being upward, and the direction opposite to the arrow is indicated ( That is, the bottom side of the tank is described as below. Further, the so-called tank bottom side refers to the tank bottom side in the tank body 1. In the present specification, the direction indicated by the arrow in the radial direction R shown in FIGS. 1A to 6 is described as the outer circumferential direction, and the direction opposite to the arrow is described as the inner circumferential direction. Further, in the respective direction axes shown in FIGS. 4A to 6 , the can axial direction C substantially coincides with the cylindrical axis direction of the forming die 50 , and the radial direction R substantially coincides with the radial direction of the forming die 50 . Therefore, in FIGS. 4A to 6 , the cylindrical axis direction of the molding die 50 and the can axis direction C are described as the can axis direction C, and the radial direction and the radial direction of the molding die 50 are not particularly limited. R is described together as the radial direction R.

(Structure of the can body) Fig. 1A and Fig. 1B are views showing an example of the configuration of the can body 1 according to the embodiment of the present invention. Fig. 1A is a front view of the can body 1 as seen from the front, and Fig. 1B is a perspective view of the can body 1 as seen obliquely from below. Further, a part of the front view shown in FIG. 1A is shown as a cross-sectional view.

As shown in FIG. 1A and FIG. 1B, the can body 1 is composed of a can body 2 having a bottle-like shape, a can lid 3, and a winding portion 4. The can body 1 of the present embodiment has a form of a bottle can in the shape of a so-called bottle. The material for forming such a can body 1 is a thin plate metal such as aluminum, aluminum alloy or steel. The material and thickness of the sheet metal forming the can body 2 and the can lid 3 can be adapted to the strength, rigidity or strength of the can body 1 required, the type of the beverage filled in the can body 1, or the manufacturing cost of the can body 1. Come to the appropriate choice.

As shown in FIG. 1A and FIG. 1B, the can body 2 has a body portion 21, a shoulder portion 22, a mouth and neck portion 23, and a curved portion 24. In the can body 2, the body portion 21, the shoulder portion 22, the mouth and neck portion 23, and The bent portion 24 is integrally formed. An example of a method of forming such a can body 2 will be described later.

The body portion 21 is a cylindrical portion that extends in the can axis direction C and corresponds to a side wall portion of the can body 1. The shape of the body portion 21 is not limited to a simple cylindrical shape as shown in FIGS. 1A and 1B. For example, in order to make the holding of the can body 1 easier, and/or to improve the appearance of the appearance, the can diameter of the body portion 21 may be increased or decreased along the can axis direction C, or may be provided in a part of the body portion 21. A concave shape, a concave-convex shape, a groove shape, or the like. Further, processing such as embossing or texture may be applied to the surface of the body portion 21.

The shoulder portion 22 is formed by being continuously extended from the body portion 21 to the upper side. The shoulder portion 22 is hollow and has a structure in which the can diameter decreases as it approaches the body portion 21 upward in the can axis direction C. The shoulder portion 22, for example, as shown in Fig. 1A, may also be constituted by a curved portion which is curved on the outer side and the inner side of the can body 2, and the tapered portion will face upward along the can axis direction C. Close to the can axis. Of course, the shoulder portion 22 may be formed only of a tapered shape or may be formed only of a curved shape. Further, a part of the shoulder portion 22 may be formed by a cylindrical shape parallel to the can axis direction C.

The mouth and neck 23 is formed continuously on the upper side of the shoulder 22. The mouth and neck portion 23 is a portion corresponding to the drinking opening of the can body 1, and has an annular configuration having an opening at the upper end. At the upper end, as shown in FIG. 1A, a curl portion can be provided. The curled portion can be formed by providing a flange at the upper end of the mouth-and-neck portion 23 and bending the flange in the outer circumferential direction. A cover that blocks the opening of the upper end can be engaged with the curled portion.

Further, a male screw portion (not shown) may be provided on the outer peripheral surface of the lower end of the upper end portion of the neck portion 23. The screw cap can be engaged with the male screw portion. Thereby, repackaging of the can body 1 will become feasible.

The curved portion 24 is formed by being continuous from the lower end of the body portion 21, and is bent in the inner circumferential direction of the can body 2, and has a groove shape that is curved toward the lower side in the can axis direction C. That is, the curved portion 24 has an annular groove shape along the outer periphery of the lower end of the can body 2. The detailed configuration of the curved portion 24 will be described later.

The can lid 3 is a member that forms the bottom of the can body 1. The can lid 3 of the present embodiment is constituted by a disk-shaped lid body 30 that occupies a central portion and a peripheral portion of the lid body 30. As shown in FIG. 1A, the can lid 3 is formed by the lid body 30, and is joined to the can body 2 by the sealing portion 4, and the opening portion at the lower end of the can body 2 is sealed. The outer diameter of the can lid 3 can be appropriately set so that the crimping portion 4 can be positioned on the inner peripheral side of the curved portion 24 as will be described later. The thickness of the can lid 3 can be appropriately set in accordance with the strength, rigidity, manufacturing cost, and the like required for the can body 1.

The crimping portion 4 is formed by enclosing the can lid 3 and the end portion of the curved portion 24 of the can body 2 opposite to the body portion 21. FIG. 2 is a partial cross-sectional view of the can body 1 for explaining the structure of the can lid 3, the enclosing portion 4, and the curved portion 24 of the present embodiment. As shown in FIG. 2, the crimping portion 4 is formed by folding and winding the peripheral edge portion 31 provided on the outer peripheral side of the cap body 30 of the can lid 3 and the end portion 25 of the curved portion 24. The crimping portion 4 is a joint portion between the can body 2 and the can lid 3, and is formed in an annular shape centering on the can axis along the circumferential direction of the can body 2 and the can lid 3. Further, the winding portion 4 is provided on the inner circumferential side of the curved portion 24, and the lower end 4A of the winding portion 4 is located above the lower end 24A of the curved portion 24 in the can axial direction C.

Further, the gap between the peripheral edge portion 31 of the crimping portion 4 and the end portion 25 of the curved portion 24 can be appropriately sealed. Such a sealing material may be, for example, a known sealing material such as a resin or a composite material. The sealing material is applied or formed on the interface between the peripheral portion 31 and the end portion 25, and the peripheral edge portion 31 and the end portion 25 are wound, whereby the peripheral edge portion 31 and the end portion 25 of the enclosing portion 4 are fixed. The gap between the two is sealed, and the airtightness of the can body 1 is more surely maintained.

When the can body 1 having such a configuration is placed on a flat surface, the lower end 24A of the curved portion 24 contacts the flat surface. That is, the lower end 24A of the curved portion 24 becomes the bottommost portion of the can body 1. At this time, the winding portion 4 is provided on the inner peripheral side of the curved portion 24 and is provided above the lower end 24A of the curved portion 24 in the tank axial direction C. As a result, when the can body 1 is placed on a flat surface, the wound portion 24 on the outer peripheral side shields the wound portion 4 on the inner peripheral side, so that the wound portion 4 cannot be seen from the outside. As a result, the configuration of the wrap portion 4 does not include the appearance of the can body 1 when the can body 1 is placed on a flat surface. Therefore, it becomes possible to design the outer appearance of the can body 1 more freely without being limited to the presence of the wind seal portion 4. Therefore, the appearance of the can body 1 can be made more excellent.

Moreover, the configuration of the peripheral portion 31 of the can lid 3 constituting the outer surface of the enveloping portion 4 can be easily obtained by the fact that the sealing portion 4 is not visible from the outside, and is not limited to the appearance of the can body 1. Change. For example, it becomes possible to change the thickness of the can lid 3 freely. Thereby, the influence of the appearance of the can lid 1 on the appearance of the can body 1 can be ignored, and the thickness of the can lid 3 can be changed in accordance with the strength, rigidity, manufacturing cost, and the like required for the can body 1.

When the conventional can body 1 in which the winding portion 4 is exposed on the bottom side of the can is dropped, the impact of the falling portion is directly applied to the winding portion 4, and the joint portion of the winding portion 4 is peeled off to make a beverage or the like. The sealing of the contents is impaired. According to the present embodiment, when the can body 1 is dropped, the winding portion 4 has entered the body portion 21 side in the can axis direction C, so that it is difficult to directly convey the impact of the falling of the winding portion 4. Therefore, even if the can body 1 is dropped, the punching force applied to the crimping portion 4 is lowered, so that the joint portion of the crimping portion 4 is prevented from being peeled off, and the sealing property can be prevented from being easily damaged.

Further, the depth of the curved portion 24 in the can axis direction C (the length from the cap body 30 to the lower end 24A of the can lid 3) and the width of the curved portion 24 in the radial direction R (the body portion 21 and the crimping portion 4) The distance between them is not particularly limited. Further, as shown in FIG. 2, the curved portion 24 of the present embodiment is formed so as to be curved downward in the direction of the can axis direction C. However, the shape of the curved portion 24 is curved by the inner circumferential direction. There is no particular limitation on a shape that protrudes downward as a whole. For example, even if the shape of the curved portion 24 is formed or the like, a shape that protrudes upward in the can axis direction C is partially generated, as long as it is from the lower end of the body portion 21 to the end of the curved portion 24. When the portion 25 is formed in a shape that protrudes downward in the tank axis direction C as a whole, the configuration of the bent portion 24 is included in the scope of the present invention.

Further, as a result of the study by the inventors, the distance H between the lower end 4A of the crimping portion 4 and the lower end 24A of the curved portion 24 shown in Fig. 2 is preferably 0.5 mm or more. When the distance H is 0.5 mm or more, regardless of the shape of the curved portion 24, the sealing portion 4 is surely shielded, and the appearance of the can body 1 does not include the configuration of the winding portion 4, which is more practical.

The configuration of the can body 1 of the present embodiment has been described above.

(Manufacturing Method of Can Body) Next, an example of a method of manufacturing the can body 1 of the present embodiment will be described. As described above, the can body 1 of the present embodiment is a so-called two-piece can formed by winding the can lid 3 at the open end on the can bottom side of the can body 2.

The method of manufacturing the can body 1 of the present embodiment will be described in detail. First, the step of winding the can body 2 and the can lid 3 in the method of manufacturing the can body 1 will be described.

In the present embodiment, DI is formed by blanking a blank of a sheet metal, thereby forming a cylindrical can having a top plate and having a can bottom side opened. Further, the shoulder portion and the neck portion are formed by press molding the top plate side of the can body. At this time, the neck portion and the neck portion are formed to have a smaller diameter than the body portion of the can body (the portion on the lower side than the shoulder portion). By press-molding the top plate side, it is possible to form the shoulder, the mouth and the neck with low working time and suppressing the wear of the material irrespective of the material of the thin metal (for example, steel having a lower moldability than aluminum). And, by trimming the top surface of the top plate, an opening is formed at the upper end of the mouth and neck. Further, the curl portion is formed by crimping the peripheral portion of the opening at the upper end of the formed neck portion.

Further, in the present embodiment, an inclined portion is formed at a lower end portion of the body portion, and the inclined portion is reduced in diameter toward the inner circumferential direction of the can body. Further, a flange portion is formed at a lower end portion of the inclined portion. The inclined portion and the flange portion are formed by a known necking process and flange processing. The inclined portion and the flange portion correspond to the curved portion 24 and the end portion 25 thereof after the winding process. Further, the connecting portion between the inclined portion and the body portion and the flange portion can be appropriately rounded. The size of the rounded corner is not particularly limited, and is appropriately adjusted in accordance with the reduction ratio in the inclined portion (the ratio of the diameter of the can in the direction of the can axis C).

After the inclined portion and the flange portion are formed, the peripheral edge portion of the can lid and the flange portion of the can body are wound by a crimping process. The sealing process is performed by a known sealing process such as a double winding. Thereby, the can lid is wound around the open end of the can body, and the can bottom of the can body 1 is formed by the cap body of the can lid.

Next, the step of press-molding the wound portion after the winding process will be described with reference to FIGS. 3 to 4C. 3 is a view for explaining an example of a configuration of the workpiece 100 immediately after the winding process and an example of a method of press-molding. As shown in FIG. 3, the workpiece 100 is composed of a can body 200 and a lid body 300, and the can body 200 and the lid body 300 are joined by the sealing portion 400. The can body 200 is composed of a cylindrical body portion 201, a substantially tapered shoulder portion 202, a substantially annular neck portion 203, a substantially inverted tapered inclined portion 204, and a substantially annular flange portion 205. The material and thickness of the workpiece 100 are based on the material and thickness of the can body 1 described above.

At this point of time, although the crimping portion 400 is located on the inner peripheral side of the inclined portion 204 due to the reduced diameter of the inclined portion 204, it is still located at the bottom of the workpiece 100. Therefore, it is conceivable that the winding portion 400 (or the lid main body 300) is press-fitted in the direction of the arrow in FIG. 3 while fixing the can body 200. Thereby, the crimping portion 400 is pressed toward the body portion 201 side of the can body 200, and therefore it is considered that as shown in FIG. 1A, the curved portion 24 becomes the bottommost portion of the can body 1, and the can body 1 is placed thereon. When it is on a flat surface, it becomes impossible to see the crimping part 400 from the exterior.

However, as a result of the study by the inventors, it has been found that the sealing property and the formability in the crimping portion 400 are deteriorated when the crimping portion 400 or the cap body 300 is simply pressed. Specifically, when the wrap portion 400 or the cap body 300 is simply pressed in, the joint portion of the cap body 300 and the can body 200 may be stretched in a direction in which they are separated from each other. As a result, the joint between the peripheral portion 301 and the flange portion 205 of the flange portion 205 is peeled off. Therefore, the sealing property of the crimping portion 400 may be deteriorated.

In addition, it is also possible to form the curved portion 24 that protrudes downward in the can axis direction C by bending the inclined portion 204 in the inner circumferential direction while fixing the can body 200, and at the same time, The crimping portion 400 is disposed above the lower end of the curved portion 24 in the tank axis direction C. However, as a result of the study by the inventors, it has been found that the operation of the winding portion 400 in the radial direction R is not restricted, so that the cover body 300 and the can body are subjected to the bending process in the inner circumferential direction of the inclined portion 204. The joint portions of 200 are stretched in directions away from each other. Therefore, the sealing property of the crimping portion 400 may be deteriorated. Further, the occurrence of the bending of the inclined portion 204 in the inner circumferential direction is shifted during the bending process. It is quite difficult to shape the shape of the inclined portion 204 into a desired shape, and the winding portion 400 is less likely to move upward in the direction of the can axis C. As a result, the winding portion 400 is disposed in the specific bending portion 24 The lower end will become quite difficult.

In this case, when the member on the bottom side of the material to be processed 100 is simply pressed in, the can body 1 having a structure in which the winding portion 4 cannot be seen from the external appearance is formed without causing molding failure. Quite difficult.

Therefore, the inventors of the present invention have finally come up with the present invention after studying it. In the present invention, in the state in which the workpiece 100 is fixed, the movement of the enveloping portion 400 in the radial direction R is restrained, and the enveloping portion 400 is pressed upward in the can axis direction C, and the inclined portion 204 is pressed. This is bent in accordance with the press-fitting, and a curved portion that protrudes downward in the tank axis direction C on the inner peripheral side is formed more than the body portion 201. At this time, the cap body 300 and the enclosing portion 400 are pressed in until the lower end of the enclosing portion 400 becomes higher than the lower end of the curved portion formed by the curved inclined portion 204 in the upper direction in the can axis direction C.

According to this technique, since the movement of the winding portion 400 in the radial direction R is restricted, when the cap body 300 and the winding portion 400 are pressed in the can axis direction C, the cap body 300 in the enclosing portion 400 is The joint portion of the can body 200 will become less likely to be stretched in the radial direction R. Thereby, the joint between the peripheral portion 301 and the flange portion 205 in the flange portion 205 is not removed, and the sealing property of the crimping portion 400 can be maintained.

Further, after the movement of the curling portion 400 in the radial direction R is restricted, when the inclined portion 204 is bent, the winding portion 400 is less likely to be stretched in the radial direction R due to the bending of the inclined portion 204. Further, by the restraining of the wind sealing portion 400, it is possible to suppress the occurrence of the deflection of the inclined portion 204 in the inner circumferential direction. Therefore, it becomes easy to shape the inclined portion 204 into a curved portion having a desired shape, and it is possible to more reliably make the lower end of the winding portion 400 above the lower end of the curved portion.

Hereinafter, an example of a manufacturing apparatus for realizing a method of manufacturing a can body according to an embodiment of the present invention and an example of the manufacturing method will be described.

4A to 4C are cross-sectional views showing an example of the configuration of the manufacturing apparatus 10 for a can body according to the embodiment. Fig. 4A shows an initial stage of the press-forming step performed by the manufacturing apparatus 10, Fig. 4B shows an intermediate stage of the press-in forming step, and Fig. 4C shows the final stage of the press-in forming step. Further, in the initial stage of the press-forming step, the punch 60 for press-molding is pushed in front of the cylindrical axis direction of the forming die 50 (that is, the can-axis direction C). The intermediate stage is the stage in which the punch 60 is being pressed, and the so-called final stage means the stage in which the punch 60 moves a prescribed distance and presses into the closed state.

Referring to Fig. 4A, the manufacturing apparatus 10 of the present embodiment includes a molding die 50 and a punch 60.

The molding die 50 is, for example, a cylindrical mold that holds the outer periphery of the workpiece 100. The molding die 50 fixes the workpiece 100 by restraining the body portion 201 of the workpiece 100 and the outer peripheral surface of the shoulder portion 202 provided in the internal space. For example, when the workpiece 100 is placed in the molding die 50, the outer peripheral surface of the body portion 201 of the workpiece 100 is brought into contact with the inner circumferential surface 50A of the molding die 50, so that the workpiece 100 is held at Forming die 50. Thereby, the movement of the body portion 201 in the can axis direction C and the radial direction R is restricted. The shape, structure, and mechanism of the molding die 50 are not particularly limited, and various configurations can be applied as long as they are a molding die that abuts and restrains the outer peripheral surface of the body portion 201.

The punch 60 is a mold for press-forming the can bottom side of the workpiece 100 that has been fixed by the molding die 50. The punch 60 is disposed on one side of the cylindrical axis direction of the molding die 50 (that is, the can axis direction C) in the internal space of the molding die 50, and is provided to be movable in the vertical direction along the circumferential axis direction. The punch 60 presses the cap body 300 and the enclosing portion 400 of the workpiece 100 provided in the molding die 50 upward in the can axis direction C, and bends the inclined portion 204 directly or indirectly toward the inner circumferential direction. A bent portion is formed. Specifically, as shown in FIG. 4A, the punch 60 of the present embodiment has a can lid restraining portion 61, a winding seal portion 62, and a curved molded portion 63, and these members are integrated to form the punch 60.

The can lid restraining portion 61 is provided to be able to abut against the lower surface of the cap body 300. At the time of press-fitting, the lid lid restraining portion 61 abuts against the lid body 300, and the offset of the lid body 300 in the radial direction R and the out-of-plane deformation of the lid body 300 can be suppressed.

The can lid restraining portion 61 is a portion that is provided to abut against the lid body 300 when the workpiece 100 is placed on the upper portion of the punch 60. In the example shown in FIG. 4A, although the can lid restraining portion 61 is provided to be able to abut the entire surface of the cap body 300, the present invention is not limited to such an example. For example, a hollow cylindrical can lid restraining portion 61 can be used, and the can lid restraining portion 61 can abut only a part (for example, an outer portion) of the cap body 300. Further, the shape of the outer edge portion of the can lid restraining portion 61 corresponds to the shape of the boundary portion between the cap body 300 and the wind seal portion 400. For example, in the example shown in FIG. 4A, the outer edge portion of the can lid restraining portion 61 is formed into a rounded shape along the curved shape of the boundary portion.

The seal sealing portion 62 is provided on the outer peripheral side of the can lid restraining portion 61, and is formed with an annular recess capable of housing the crimping portion 400. As shown in FIG. 4A, at the time of press-fitting, the winding portion 400 is housed in the concave portion of the wind seal portion 62 to restrain the movement of the wind seal portion 400 in the radial direction R. The position at which the concave portion of the wind seal portion 62 is provided in the punch 60 is a position facing the wind seal portion 400, and can be appropriately adjusted in accordance with the processing position of the wind seal portion 400 in the workpiece R in the radial direction R. . The ideal range of the diameter of the crimping portion 400 will be described later.

The width of the concave portion of the wind seal restraint portion 62 can be appropriately adjusted to be substantially the same as the width of the wind seal portion 400 formed by the crimping process in the radial direction R. Thereby, the restraint of the movement of the winding portion 400 in the radial direction R can be made more reliable. Further, although the depth of the concave portion of the winding seal portion 62 is not particularly limited, the depth of the concave portion is preferably a length from the cover main body 300 to the lower end of the wind seal portion 400 in order to reliably accommodate the wind seal portion 400 in the concave portion. the above. Thereby, it becomes possible to more reliably prevent the molding failure of the cap body 300 in the vicinity of the enclosing portion 400 from occurring. Further, the bottom of the concave portion of the crimping and restraining portion 62 may not be provided.

The curved molded portion 63 is an outer peripheral side of the wound seal portion 62 and is a portion provided on the inner peripheral side of the inner peripheral surface 50A of the molding die 50. The curved formed portion 63 has a molding surface 63A for abutting against the bent inclined portion 204 to form a curved portion 24 that protrudes downward in the can axis direction C. That is, the molding surface 63A is an annular groove having a curved shape corresponding to the curved portion 24, and the cross-sectional shape of the molding surface 63A has a shape that is curved to protrude downward.

When the punch 60 is pushed in above the can axis direction C while being in contact with the workpiece 100, a bending deformation that is bent upward is generated in a part of the inclined portion 204. It is also possible that the portion where the bending occurs is a portion where the portion near the boundary between the curling and sealing portion 62 and the boundary portion between the curling and sealing portions 62 is in contact with each other. The portion on the outer peripheral side where the bending portion of the inclined portion 204 is generated is pressed toward the upper side of the punch 60, and protrudes more downward than the portion where the bending occurs. Thereafter, the portion on the outer peripheral side of the inclined portion 204 that protrudes downward is abutted against the molding surface 63A, and is formed into a shape that is deformed and curved along the molding surface 63A. Thereby, the curved portion 24 of the can body 1 is formed.

Further, as shown in Fig. 4A, the depth H _A of the curved portion in the forming surface 63A of the curved formed portion 63 (the length in the can axial direction C from the upper surface of the can lid forming portion 61 to the lower end of the forming surface 63A) It is larger than the length H _B in the can axis direction C of the crimping portion 400 of the workpiece 100. Thereby, in the can body 1 after molding, the lower end of the winding portion 4 becomes higher than the lower end 24A of the curved portion 24 in the tank axis direction C.

Further, the shape and size of the molding surface 63A can be adjusted according to the height of the inclined portion 204 (the length from the lower end of the body portion 201 to the lid body 300 in the can axis direction C, that is, the length of the reduced diameter portion), or the winding portion. The position and size of the 400 are appropriately set.

Next, a press-molding step using the manufacturing apparatus 10 will be described with reference to FIGS. 4A to 4C.

First, in the initial stage of the press-forming step shown in FIG. 4A, the body part 201 is restrained by the forming die 50 to fix the workpiece 100, and the cap body 300 is placed on the punch 60. At this time, the cap body 300 abuts against the can lid restraint portion 61, and the cap sealing portion 400 is in a state of being housed in the cap seal restraint portion 62. Further, the curved molded portion 63 may not be in contact with the inclined portion 204 in the initial stage of the press-molding step.

Next, in the intermediate stage of the press-forming step shown in FIG. 4B, the punch 60 is moved upward along the inner circumferential surface 50A of the molding die 50 toward the can axis direction C, and the cap body 300 and the crimping portion 400 are pressed upward. At the same time, the bending process of the inclined portion 204 is performed at the same time. At this time, as shown in FIG. 4B, for example, the abutment portion of the inclined portion 204 and the curved molded portion 63 can be bent upward by press-fitting by the curved formed portion 63.

In the intermediate stage of the press-forming step, the movement of the cover body 300 and the winding portion 400 in the radial direction R is restricted by the can lid restraining portion 61 and the winding seal portion 62, respectively. As a result, by restraining the wind seal portion 400 and simultaneously displacing the wind seal portion 400 upward, a compressive force in the in-plane direction is generated in the inclined portion 204. Thereby, buckling can be generated in the bent portion of the inclined portion 204. That is, the bending deformation of the inclined portion 204 is not caused by the direct bending of the inclined portion 204 by the punch 60, but can be generated by the buckling of the inclined portion 204 by the restraint of the crimping portion 400, and Buckling is caused by the compressive force in the in-plane direction. As a result, since the reaction force from the inclined portion 204 is applied to the winding portion 400, it is difficult to apply the tensile force in the radial direction R. Therefore, peeling of the joint portion of the wind seal portion 400 can be suppressed, and the sealing property of the wind seal portion 400 can be maintained. Further, the buckling (that is, the bending deformation) in the inclined portion 204 may be caused not at the abutment with the curved formed portion 63 as shown in FIG. 4B but at the other portion.

Further, in the final stage of the press-forming step shown in FIG. 4C, the inclined surface 204 is formed to be curved downward along the forming surface 63A of the curved formed portion 63 of the punch 60. Such a curved shape is formed in a portion on the outer peripheral side of the portion where the bending deformation of the inclined portion 204 is generated. The inclined portion 204 after such deformation becomes the curved portion 24 in the can body 1. In this final stage, the punch 60 is pushed in from the tank bottom side upward until the lower end of the winding portion 400 becomes higher than the lower end of the curved portion 24 formed from the inclined portion 204 in the tank axis direction C. until. Therefore, in the can body 1 obtained after the press-molding step, the can body 1 can be seen from the outside by the curved portion 24 when the can body 1 is placed on the flat surface. The state of the seal 4.

Further, the final position of the punch 60 in the final stage of the press-forming step is preferably between the lower end of the crimped portion 4 that has been pressed and the lower end of the bent portion 24 that has been formed in the can axis direction C. The distance will be 0.5mm or more. As described above, when the distance H is 0.5 mm or more, regardless of the shape of the curved portion 24, the sealing portion 4 is surely shielded, and the appearance of the can body 1 does not include the configuration of the winding portion 4, which becomes more practical. .

Through the above press-forming step, the can body 1 having the structure in which the winding portion 4 is on the inner peripheral side of the curved portion 24 and the lower end of the winding portion 4 is located more than the lower end of the curved portion 24 can be manufactured. The upper one of the axial direction C.

In addition, the configuration of the can lid restraining portion 61, the winding seal restraint portion 62, and the curved molded portion 63 forming the punch 60 is not limited to the configuration described in FIGS. 4A to 4C. These configurations can be appropriately designed in accordance with the position, size, and shape of the cover body 300, the enclosing portion 400, and the inclined portion 204 of the workpiece 100 to be processed.

Moreover, the inventors have further studied the results and found that the diameter of the sealing portion 400 (as shown in FIG. 4A, the position of the can body 200 from the can shaft to the bottom of the winding portion 400 in contact with the lid body 300) When the length is twice as long as the predetermined length, it is possible to more reliably suppress the molding failure caused by press-fitting. Specifically, the body portion 201 of the tank size (diameter than the circumferential surface of the body portion 201) is D _1, the diameter of the seaming portion 400 is D _2, should satisfy the following equation (1). When D ₂ ≧0.75×D ₁ , it is possible to suppress the occurrence of wrinkles which are wrinkles which are affected by the work hardening caused by the diameter reduction processing of the inclined portion 204 . Moreover, the number of steps of the diameter reduction processing can be reduced, which is also advantageous from the viewpoint of cost. In addition, when D ₂ ≦ 0.88 × D ₁ , when the inclined portion 204 is bent and deformed, it is possible to suppress the crop-like interference between the enveloping portion 400 and the inclined portion 204, and the curling portion 400 does not rub against the inclined portion 204. In the case where a flaw is generated, the forming accuracy of the curved portion 24 can be improved.

0.75×D ₁ ≦D ₂ ≦0.88×D ₁・・・Formula (1)

The method of manufacturing the can body 1 and the manufacturing apparatus 10 of the present embodiment have been described above. [Examples]

Next, an embodiment of the present invention will be described. In order to confirm the effect of the present invention, in the present embodiment, the performance of the can body 1 manufactured by the manufacturing method of the above-described embodiment and the manufacturing apparatus 10 was verified. Further, the following examples are merely examples for verifying the effects of the present invention, and the present invention is not limited to the following examples.

In the present embodiment, the can body 1 obtained by pressing the winding portion 400 of the workpiece 100 from the tank bottom side upward by using the manufacturing method and the manufacturing apparatus 10 of the above-described embodiment, evaluates the can body 1 The external visibility of the crimping portion 4, the peeling of the joint portion, and the formability of the curved portion 24 indicate the effectiveness of the present manufacturing method and the manufacturing apparatus 10. In the evaluation, the external visibility of the enveloping portion 4 is determined by whether the wrap portion 4 is seen from the outside of the can body 1 when the formed can body 1 is placed on a flat surface. The presence or absence of the peeling of the joint portion of the wind seal portion 4 is determined by whether or not peeling of the joint portion between the can lid 3 and the can body 2 of the wind seal portion 4 is observed. Moreover, the formability of the curved portion 24 is determined by the presence or absence of flaws or wrinkles or the like which are generated in the curved portion 24.

The test conditions and evaluation results are shown in Table 1 below. As the test conditions, the configuration of the punch used, the can diameter D ₁ (mm) of the body part 201 of the workpiece 100, and the diameter D ₂ (mm) of the crimping portion 400, and the crimping portion 400 were used. the diameter D ₂ of the can diameter ratio D ₁ D ₂ / D _1, and an inclined portion 204 of the height H _S (mm). Here, the height H _{S of the} inclined portion 204 is the length in the can axis direction C from the lower end of the body portion 201 to the cap body 300 as described above, that is, the length of the reduced diameter portion in the can axis direction C. The can body formed by the punch and the workpiece to be subjected to such test conditions was evaluated for the external visibility of the crimping portion, the presence or absence of peeling, and the formability of the bent portion. In addition, the thickness of the can body 200 and the lid main body 300 which comprise the to-be-processed material 100 used in each Example and the comparative example was set to 0.35 mm, respectively. Moreover, the material of the workpiece 100 is set to T2 of JIS G3303 of a soft steel plate.

[Table 1]

Further, in the first to fifth embodiments, the workpiece 100 was press-formed using the punch 60 shown in Fig. 4A. The can lid restraint portion 61, the curl seal portion 62, and the curved molded portion 63 are appropriately designed as a cover body in accordance with the can diameter D _{1 of the} body portion 201, the diameter D _{2 of the} crimp portion 400, and the height H _{S of the} inclined portion 204. The can lid binding portion 61 can be abutted, the wind sealing portion 400 can be accommodated in the wind seal restraint portion 62, and the inclined portion 204 can be deformed along the molding surface 63A of the curved molded portion 63.

Further, in Comparative Examples 1 to 3, the workpiece 100 was press-formed using the punch 600 shown in Fig. 5 . The punch 600 shown in Fig. 5 is constituted only by a curved formed portion 601 having a forming surface 601A. That is, when such a punch 600 is used, the inclined portion 204 can be directly bent by the curved forming portion 601. Further, in Comparative Example 4, the workpiece 100 was press-formed using the punch 610 shown in FIG. The punch 610 shown in Fig. 6 is constituted only by the can lid restraining portion 611. That is, when such a punch 610 is used, the cover body 300 is pressed upward from the tank bottom side, and bending deformation can be caused in the inclined portion 204.

The evaluation results will be described with reference to Table 1. In the can body 1 after the molding of the first to fifth embodiments, when the can body 1 is placed on a flat surface, the sealing portion 4 is not seen from the outside, and the joint portion of the winding portion 4 is not confirmed. Peeling and confirming that the sealability was maintained. In the first embodiment, although a slight wrinkle is observed in the curved portion 24 of the can body 1, since it is a wrinkle formed on the bottom side of the can, it is not seen when the can body 1 is placed on a flat surface. To the wrinkles. In the second to fifth embodiments, wrinkles and flaws were not observed in the curved portion 24 of the can body 1, and it was confirmed that the curved portion 24 was formed in a shape corresponding to the molding surface 63A.

In addition, according to the evaluation results of Examples 3 to 5, it was confirmed that the can body 1 having excellent moldability can be obtained irrespective of the height H _S of the inclined portion 204.

On the other hand, when the can body 1 was placed on a flat surface, the can body 1 was seen from the outside, and the winding portion was confirmed from the outside. The peeling of the joint portion of 4, in turn, the formation of the bent portion 24 is insufficient. This is considered to be because the inclined portion 204 is directly bent by the bending forming portion 601, so that the winding portion 4 is stretched in the radial direction R to cause peeling of the joint portion. Further, it is considered that the bending portion 24 is unstable due to the occurrence of the bending of the inclined portion 204, and the winding portion 4 is not sufficiently pressed upward from the tank bottom side. Therefore, the bending portion 24 is formed with low precision, and the can body 1 is placed on the flat surface. The sealing portion 4 is exposed when the surface is on the surface.

Further, in the can body 1 of Comparative Example 4, although the peeling of the joined portion of the crimping portion 400 was not remarkable as compared with the can body 1 of Comparative Examples 1 to 3, it was observed in a part. Further, the winding portion 400 interferes with the inclined portion 204 that has been bent, so that the winding portion 4 is not pressed, and is exposed when the can body 1 is placed on a flat surface. In this case, it is considered that the cap body 300 is press-fitted only by the can lid restraining portion 611, so that the restraining of the crimping portion 400 and the control of the bending deformation of the inclined portion 204 are insufficient.

According to the present embodiment, in order to manufacture the can body 1 which maintains the sealing property of the sealing portion 4 and the winding portion 4 is not visible from the outside, the workpiece 100 is processed from the can bottom of the workpiece 100 using the punch 60. It is effective to press the side up, and the punch 60 is provided with the can lid restraining portion 61, and is in contact with the lid body 300 of the workpiece 100, and is restrained; the crimping and restraining portion 62 is housed, and the bellows portion 400 is housed and restrained. The movement of the radial direction R and the curved molding portion 63 have a molding surface 63A in which the inclined portion 204 that is bent and deformed is formed into a curved shape that protrudes downward. And showing the seaming portion 400 by the outer diameter D ₂ with respect to the outer diameter D of the body portion 201 is set to _a predetermined range of sizes, to enhance the formability of the bent portion 24 is feasible.

Although the preferred embodiments of the present invention have been described in detail above with reference to the drawings, the invention is not limited by the examples. It is obvious that various modifications and examples can be conceived within the scope of the technical idea described in the claims. It is understood that it falls within the technical scope of the present invention.

For example, in the above embodiment, the can body 1 is formed into a bottle shape having the shoulder portion 22, but the present invention is not limited to such an example. For example, the can body may also be a substantially cylindrical can body. Further, in the above embodiment, the can body 1 is a can made by DI molding, but the present invention is not limited to such an example. For example, the can body may be a can made by DR forming or a so-called 3-piece can. Further, in the above-described embodiment, the can body 1 has been described as a can body suitable for use in a beverage can. However, the can body to be held by filling the contents therein is not limited. That is, the present invention can be applied to any can body regardless of the material, the use, the size, and the molding method of the can body as long as it is a can body formed by the can bottom of the can body.

1‧‧‧ tank

2, 200‧‧‧ cans

3‧‧‧ can lid

4,400‧‧‧The seal department

4A‧‧‧Bottom

10‧‧‧ Manufacturing equipment

21, 201‧‧‧ Body Department

22, 202‧‧‧ shoulder

23, 203‧‧‧ mouth neck

24‧‧‧Bend

24A‧‧‧Bottom

25‧‧‧End of the bend

30, 300‧‧ ‧ cover ontology

31, 301‧‧‧ Peripheral Department

50‧‧‧ Forming die

50A‧‧‧ inner circumference

60, 600, 610‧‧ ‧ punches

61, 611 ‧ ‧ can lid restraint

62‧‧‧The Department of Restriction

63, 601‧‧‧Bending forming department

63A, 601A‧‧‧ forming surface

100‧‧‧Processed materials

204‧‧‧ inclined section

205‧‧‧Flange

D1‧‧‧ can diameter

D2‧‧‧ diameter

C‧‧‧can axis direction

R‧‧‧Path

H‧‧‧ distance

HA‧‧‧depth

HB‧‧‧ length

HS‧‧‧ Height

Fig. 1A is a front elevational view showing an example of a configuration of a can body 1 according to an embodiment of the present invention. Fig. 1B is a perspective view of the can body 1 of the same embodiment as seen obliquely from below. Fig. 2 is a partial cross-sectional view showing the can body 1 of the structure of the can lid 3, the enclosing portion 4, and the curved portion 24 of the embodiment. 3 is a view for explaining an example of a configuration of the workpiece 100 immediately after the winding process and an example of a method of press-molding. Fig. 4A is a cross-sectional view (initial stage) showing an example of a configuration of a manufacturing apparatus 10 for a can body according to the embodiment. Fig. 4B is a cross-sectional view (intermediate stage) showing an example of the configuration of the can manufacturing apparatus 10 of the same embodiment. Fig. 4C is a cross-sectional view (final stage) showing an example of the configuration of the can manufacturing apparatus 10 of the same embodiment. Fig. 5 is a cross-sectional view showing the configuration of a manufacturing apparatus of a can body of Comparative Example 1. Fig. 6 is a cross-sectional view showing the configuration of a manufacturing apparatus of a can body of Comparative Example 2.

Claims (6)

A can body having a can bottom under the direction of the can axis, comprising: a can lid to form the can bottom; the can body comprising: a body portion, being cylindrical and extending in the direction of the can axis; The bent portion is continuous from the lower end of the body portion, and is curved to protrude downward from the body portion on the inner peripheral side; and the wind seal portion is provided on the inner peripheral side than the curved portion, and is sealed by the seal An end portion of the curved portion opposite to the body portion and a peripheral portion of the can lid, and the can lid and the can body are joined, and a lower end of the crimping portion is located more than a lower end of the curved portion the top of the tank in the axial direction, the diameter D of the can body portion of _a diameter D (mm) and the seaming portion ₂ (mm) satisfy the following equation _{(1): 0.75 × D 1} ≦ D 2 ≦ 0.88 × D ₁ ...form (1). The can body of claim 1, wherein the can body further comprises: a shoulder portion extending from the body portion toward the upper side, and the can diameter is decreased as approaching from the body portion toward the top along the can axis direction; and the neck portion The portion is extended from the shoulder toward the upper side, has a smaller diameter than the body portion, and has an opening at the upper end. A method for producing a can body, which is a method for producing a can body having a can bottom at a lower side in a can axis direction, comprising: a fixing step of fixing a material to be processed; and a forming step of forming the fixed workpiece to be processed, the Processing materials include: a body portion having a cylindrical shape and extending in the direction of the can axis to constitute a side wall portion of the can body; an inclined portion extending from a lower end of the body portion, and a can diameter extending from the body portion toward the can axis direction The cover body is formed to be close to the bottom; the cover body is formed to form the can bottom; and the wind seal portion is formed by winding a lower end portion of the inclined portion and a peripheral portion of the cover body, and engaging the cover body and the body portion, In the fixing step, the workpiece is fixed by a molding die that restrains the outer peripheral surface of the body portion, and in the molding step, the movement of the winding portion in the radial direction is restrained, and the cover body and the aforementioned seal are sealed. The portion is press-fitted upward in the direction of the can axis, and the inclined portion that is bent in accordance with the press-fitting is formed into a curved portion that protrudes toward the lower side in the inner peripheral side than the body portion, and the cover body and the roll are formed. The sealing portion is press-fitted until the lower end of the winding portion is positioned higher than the lower end of the curved portion formed by bending the inclined portion in the tank axis direction. The curved portion is a punch that is disposed on one side of the molding die in the cylindrical axis direction of the molding die, and is in contact with the cap body and the winding portion. The bottom side is press-fitted into the upper side in the direction of the can axis, and the punch is a punch integrally formed by the following member, and includes a can lid restraining portion that is capable of abutting against a lower surface of the cover body; The seal sealing portion is provided on the outer peripheral side of the can lid binding portion, and has a concave portion capable of accommodating the wind seal portion, and a curved molded portion provided on the outer peripheral side of the seal sealing portion and curved to protrude downward The molding surface, and the depth of the curved portion in the molding surface is larger than the length of the winding portion in the direction of the can axis. The method of manufacturing a body of a request of item 3, wherein the diameter D of the can body portion _1, the diameter D (mm) and the seaming portion ₂ (mm) satisfy the following equation _{(1): 0.75 × D 1} ≦ D 2 ≦0.88×D ₁ ...formula (1). The method of manufacturing a can body according to claim 3 or 4, wherein the material to be processed further comprises: a shoulder portion extending from the body portion toward the upper side, and the can diameter is approached upward from the body portion along the direction of the can axis And the neck and the neck are extended from the shoulder to the upper side, have a smaller diameter than the body part, and have an opening at the upper end. A manufacturing apparatus for a can body, which is a manufacturing apparatus for a can body having a can bottom below a can axis direction, comprising: a molding die for fixing a workpiece; and a punch placed on the inner side of the molding die One side of the mold in the direction of the cylindrical axis, the workpiece is molded together with the molding die, and the workpiece includes a body portion that is cylindrical and extends in the direction of the can axis to constitute a side wall portion of the can body; The inclined portion is continuous from the lower end of the body part, and the can diameter is along the front The can axial direction decreases from the body portion toward the lower side; the cover body forms the can bottom; and the winding portion is formed by winding a lower end portion of the inclined portion and a peripheral portion of the cover body, and joining the aforementioned In the cover body and the body part, the molding die fixes the workpiece by restraining the outer peripheral surface of the body part, and the punch is a punch integrally formed of the following member, and includes a can lid restraining portion, and is configured to be capable of a sealing portion is provided on the outer peripheral side of the can lid binding portion, and has a concave portion that can accommodate the winding portion, and a curved portion that is provided in the winding seal portion. The outer peripheral side has a molding surface that is curved to protrude downward in the direction of the can axis, and the depth of the curved portion in the molding surface is larger than the length of the winding portion in the direction of the can axis, and the punch is configured to be capable of In a state in which the cover body and the winding portion are brought into contact with each other, the inner circumferential surface of the molding die is moved upward from the tank bottom side.